A variety of lift devices are known in the prior art for moving invalid or handicapped persons from one position to another. In fact, there are several devices disclosed in the prior art which have been found useful specifically for moving persons from the poolside to the pool and back again, or movement to and from a bathtub and the like.
Such devices suffer from flaws in operation, safety, or convenience and the inventor herein, familiar with such devices as a result of having worked in the field for several years, noted these flaws and devised an apparatus which tends to overcome most, if not all, of such shortcomings.
One such device of the prior art can be found in U.S. Pat. No. 4,606,082, issued on Aug. 19, 1986 to Kuhlman. Kuhlman discloses a lift apparatus for transferring a person of limited mobility to and from a restricted area such as a raised tub-like water treating facility, and in particular such an apparatus which is particularly adapted for transfer from and to a wheelchair without requirement of the individual standing during the transfer process. It is noted that this device requires an overhead support system, which would not tend to be accommodating to a poolside.
A second device which is useful in bathtubs and the like is disclosed by Schaffer in U.S. Pat. No. 5,129,112, which issued on Jul. 14, 1992. This device is attachable to the side walls of a bathtub enclosure. It does provide for an operator device which can be controlled by the user of the device. However, this device would not be useful at the poolside for two reasons, namely, it needs sidewall support, and it does not move the loading operation far enough from the edge of the pool as does the device of the instant invention.
Grimes, et al, in U.S. Pat. No. 4,183,106, issued Jan. 15, 1980, discloses a motorized lift that supports a chair at the side of a pool in a position to receive a handicapped person as shown in FIG. 1. The chair is rotated out over the water, as indicated by the directional arrows in FIG. 1, and is then lowered into the water, whereupon the occupant slides or pushes off the chair for swimming or a therapy session. The chair is adapted to receive the person after the session, and is then raised out of the water, and rotated back to the initial pool side position, so that the person can leave the chair with a minimal amount of difficulty. This device has as its shortcomings, the inability of providing the loading of the user away from the edge of the pool, and, the user must have a second person manipulate the controls.
A third device is that disclosed in Nolan, U.S. Pat. No. 4,221,008, which issued Sep. 9, 1980, which discloses a swimming pool chair lift wherein a patient may be transported vertically, in a helical pattern, into and out of a pool of water or similar liquid. The chair lift includes an L-shaped seat 6, hydraulic cylinder means 8 adapted to receive the seat, and is activated by a particular fluid at a selected pressure. Guide means, such as cam 12 and follower 11, follow a helical path as the cylinder is moved vertically along the cam into, and out of, the pool of the liquid. The carrier can thus be lowered, or raised, out of the pool, while being rotated through an arc that enables the disabled person to be transported to a stable pool side position. This device has the shortcoming that it uses a hydraulic system to power the seat and apparatus. Further, it has the disadvantage of not being able to be mounted a fair distance from the side of the pool.
A second Nolan patent is U.S. Pat. No. 4,996,728, which issued Mar. 5, 1991, and which deals with portable lift structures much like that disclosed in the '008 patent, except that the hydraulic means is separated from the support means such that the descent and ascent is not exactly vertical. This device suffers from the same defects as the first Nolan device, in that, it uses a hydraulic system and it has to be mounted adjacent the pool edge.
The device of the instant invention overcomes some or all of the problems associated with the prior art devices.